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The Lasso and Ridge estimators are effective variable selection methods for a simple linear model. While the multiple linear model is often used in practice, only few studies have examined its problem of variable selection. To address this gap, we study such problem by taking advantage of the Lasso and Ridge estimate. We propose two variable selection methods in the multiple linear model and introduce the multiple random simulation (MRS) algorithm, whose efficiency is similar to that of the least angle regression (LARS) algorithm in a simple linear model. We verify the performance of these two algorithms by applying them to real diabetes data and find that the LARS algorithm cannot be easily applied in a multiple linear model. We also illustrate the excellent performance of MRS by applying this algorithm on a simulated dataset. [ABSTRACT FROM AUTHOR]

This study selected the Yangtze River Delta urban agglomeration as the research area, considering the current status of its transportation development to construct an urban agglomeration land transportation integration index system and to evaluate the development of the area's transportation integration. The study examined the influence mechanism of transportation infrastructure on service industry agglomeration. The results were as follows: (1) From 2011 to 2020, the Yangtze River Delta urban agglomeration land transportation integration index showed a clear upward trend. (2) The development of the integration level of local transportation has a certain inhibitory effect on the agglomeration of local service industries. The transportation integration of the Yangtze River Delta urban agglomeration played an important role in promoting the agglomeration of local wholesale and retail industries and transportation, storage, and postal services. The labor force and market size also have a significant impact on service agglomeration. (3) The integration of land transport in the urban agglomeration affects the agglomeration of service industries through the knowledge spillover effect caused by the improvement of accessibility, and the impact is heterogeneous. The Yangtze River Delta urban agglomeration needs to accelerate the construction of trans-provincial and trans-municipal transportation infrastructure and to further improve its connectivity level to promote the integrated development of high-quality transportation in this area. [ABSTRACT FROM AUTHOR]